Tag Archives: test pilot

Aviation

Test Pilot: 101

Test Pilot, one of the most glamorous titles for a pilot, right? Well, sort of. The adage goes, if you deviate from limits or design you become a test pilot. This usually is intended to make you think twice before deviating from said limits and/or design. In the movies the Test Pilot usually pulls up just before impacting terra firma, or in the more intense films he ends up climbing out of the smoking or maybe not. The realities of flight testing seem to be that it is a much more mundane job, or at least it is supposed to be. When it gets exciting, something has gone wrong.

None of this comes from experience as of yet, it comes from doing some research on test flying amateur-built experimental aircraft. I have been wanting to build or restore an airplane for a long time and as the primary worker-bee I want the spoils of war, namely, I wan to test fly my work. Many experimental builders think of the test period required for the airworthiness certificate is just the need to fly off the 40 hours without attracting any attention from the FAA or NTSB; this was never how I saw the test flight. I had always planned on a full and thorough flight test program but I wasn’t really sure what that was.

Flight testing is apparently akin to an aviation black-magic that only a few initiates have a deeper understanding of, or at least that what it seemed like. After poking around on the internet for a couple of years I gathered a few resources but was still somewhat in the dark. Many moons ago I put a book on my Amazon wishlist “Flight Testing Homebuilt Aircraft” by Vaughan Askue. This was the only reasonably priced reference book I could find and it didn’t require an engineering degree to read the table of contents. This week I finally purchased the book. I am only about half way through and already I have had dozens of ah-ha moments of clarity that merged my pilot brain and mechanic brain in a way that they both benefited from the point.

As I said, I’m only about half way through this reading, I am sure I will be reading this book several more times. The biggest thing I have learned is that a good flight test program begins long before a single part is constructed or reconstructed as the case may be. Since I am inclined to move into restorations what this means for me is that I need to start thinking about the flight test program before I start the work.

By approaching the restoration as a test pilot as well as a mechanic I can head off some of the things that slow down all of the phases of a project, as a mechanic it gives me a closer relationship with the airplane from a systems and structural perspective.

I will be finishing the first read of the book fairly soon and I am looking forward to putting some of this new found  associative knowledge to good use.

Blue skies and tailwinds,
~FlyBoyJon 

Aviation, Projects

Flyboys

One of my favorite movies is Flyboys (2006) by Tony Bill. Some of my favorite scenes in the movie are the ones where the pilots gather in the Ready Room, aka the pub. They celebrate their successes and remember their losses in a way that many non-pilots can’t truly understand.

Viper (Tom Skarret’s character in Top Gun) said it best: “A good pilot is compelled to always evaluate what’s happened, so he can apply what he has learned.” From outside the aviation world it may seem as though pilots are obsessed with death and accidents, and very callus about these situations. In one sense we are; from the day we start flight training, we are constantly exposed to aviation accident reports. Like most pilots with a few hundred hours, I know pilots who have died in an airplane, or been involved in a reportable event. More often than not the cause of the crash or event was Pilot Error.

Pilot Error seems to be the NTSB’s favorite phrase in accident reports, it appears in almost all of them. Sadly, it’s a legitimate statement in those reports far more often than not. This is why we read the reports; if that guy did it, I might do it, too. I have to pay attention to that. A well educated aviator might push the limits, but they know exactly where those limits are and how they affect the situation.

I am still in the planing phase of my aircraft build project but I am thinking about the Flight Testing phase. Before I can develop a Flight Test Program I need to have a good understanding of the Volksplane’s flight characteristics from other builders and pilots. I plan on asking a lot of questions on the boards and lists but if I want to ask intelligent and directed questions I need to know what to ask. My first stop in researching flight characteristics is the NTSB Aviation Accident Database.

According to the FAA’s Registration Database there are approximately 512 Volksplane variants currently registered in the U.S. Since the plans for the aircraft were made available in 1969 there have been 45 Volksplane accidents; 17 none/minor injury, 19 serious injury, 9 fatalities, they break down by decade as follows.

  2000 1990 1980 1970
Fatal 1 2 2 4
Non Fatal 2 4 9 21

Not all data fields add up numerically, mainly because the NTSB’s data in not always complete so keep that in mind before you pull out that calculator. In the case of our accident pilots only 44 were reported with a certificate status, 38 had a pilot certificate and 5 did not. I broke down pilot age into three groups. The under 30 set included 8 pilots, in the 31-49 group we found our majority with 22, the over 50 group claimed 12.

Let’s take a look at total pilot in command (PIC) hours and hours in type.

  ≤50 ≤100 ≤250 ≤500 ≥500
TTL Hrs 1 4 11 8 19
 
  ≤5 ≤25 ≤50 ≥50  
In Type 24 9 4 5  

Yes, that’s right. A couple of our intrepid certificateless pilots had reported over 100 hours.

A majority of the reports involved a loss of control in the air, 25, with several on the ground, 16. One (1) incident was due to weather and one (1) was due to a propeller failure.

18 incidences involved some kind of power failure, 8 from unknown causes, 10 from fuel issues, 5 of which were caused by fuel starvation, 2 of those from just old fashioned running out of gas.

There were 15 incidents of builders not installing parts, installing parts wrong, ground testing with known problems that ended up as unintentional in-flight problems.

Most of the mechanical stuff and incidents of pilots without certificates occurred in the 70s. The disturbing part is pilots with low total times and no time in type are more common in recent decades. It seems as though we have gotten better in the building part but more impatient about getting the bird in the air.

My conclusions from this basic data are that as a builder it is of the utmost importance to take your time and check everything thrice. As a test pilot, take your time, inspect everything, understand the flight characteristics of the aircraft, expected and otherwise, be current, in type if possible, and take each step of the test flight program with absolute attention to detail. Considering every flight as a test flight up to 100 hours is not a bad idea ether. There was only one incident over 100 hours. Attention to detail and planning could have prevented all of the 45 incidents with possible exceptions for 2 of them.

Did I learn anything I didn’t know? No. Did taking the time to do the research make me think a bit more about how to prevent failures and what might go wrong? You betcha! Will my standards in the build process be better than if I had not taken the time to do this research? Probably. How about flight testing standards? Yeah. I think I will be less ambitious with the test flight schedule.

Until next time, blue skies and tail winds,
~FlyBoyJon

BTW Just in case you are wondering, I have been known as FlyBoyJon since 2003.